7,667 research outputs found
Effect of Piper betle and Brucea javanica on the Differential Expression of Hyphal Wall Protein (HWP1) in Non-Candida albicans Candida (NCAC) Species
The study aimed to identify the HWP1 gene in non-Candida albicans Candida species and the differential expression of HWP1 following treatment with Piper betle and Brucea javanica aqueous extracts. All candidal suspensions were standardized to 1 x 10(6) cells/mL. The suspension was incubated overnight at 37 degrees C (C. parapsilosis, 35 degrees C). Candidal cells were treated with each respective extract at 1, 3, and 6 mg/mL for 24 h. The total RNA was extracted and reverse transcription-polymerase chain reaction was carried out with a specific primer of HWP1. HWP1 mRNAs were only detected in C. albicans, C. parapsilosis, and C. tropicalis. Exposing the cells to the aqueous extracts has affected the expression of HWP1 transcripts. C. albicans, C. parapsilosis, and C. tropicalis have demonstrated different intensity of mRNA. Compared to P. betle, B. javanica demonstrated a higher suppression on the transcript levels of HWP1 in all samples. HWP1 was not detected in C. albicans following the treatment of B. javanica at 1 mg/mL. In contrast, C. parapsilosis and C. tropicalis were shown to have HWP1 regulation. However, the expression levels were reduced upon the addition of higher concentration of B. javanica extract. P. betle and B. javanica have potential to be developed as oral health product.Article Link :
http://www.hindawi.com/journals/ecam/2013/397268
Accurate Band Gaps for Semiconductors from Density Functional Theory
An essential issue in developing semiconductor devices for photovoltaics and thermoelectrics is to design materials with appropriate band gaps plus the proper positioning of dopant levels relative to the bands. Local density (LDA)
and generalized gradient approximation (GGA) density functionals generally underestimate band gaps for semiconductors and sometimes incorrectly predict
a metal. Hybrid functionals that include some exact Hartree-Fock exchange are known to be better. We show here for CuInSe_2, the parent compound of the promising CIGS Cu(In_xGa_(1-x))Se_2 solar devices, that LDA and GGA obtain gaps of 0.0-0.01 eV (experiment is 1.04 eV), while the historically first global hybrid functional, B3PW91, is surprisingly better than B3LYP with band gaps of 1.07 and
0.95 eV, respectively. Furthermore, we show that for 27 related binary and ternary semiconductors, B3PW91 predicts gaps with a mean average deviation (MAD) of only 0.09 eV, which is substantially better than all modern hybrid functionals
Can a wormhole generate electromagnetic field?
We have considered the possibility of a slowly rotating wormhole surrounded
by a cloud of charged particles. Due to slow rotation of the wormhole, the
charged particles are dragged thereby producing an electromagnetic field. We
have determined the strength of this electromagnetic field and the
corresponding flux of radiation.Comment: 9 pages, typos fixe
Branching Ratio and CP-asymmetry for B-> 1^{1}P_{1}gamma decays
We calculate the branching ratios for B_{d}^{0}->(b_{1},h_{1})gamma at
next-to-leading order (NLO) of alpha_{s} where b_{1} and h_{1} are the
corresponding radially excited axial vector mesons of rho and omega
respectively. Using the SU(3)symmetry for the form factor, the branching ratio
for B_{d}^{0}->(b_{1},h_{1})gamma is expressed in terms of the branching ratio
of the B_{d}^{0}-> K_{1}gamma and it is found to be
B(B_{d}^{0}->b_{1}gamma)=0.71* 10^{-6} and B(B_{d}^{0}-> h_{1}gamma)
=0.74*10^{-6}. We also calculate direct CP asymmetry for these decays and find,
in confirmity with the observations made in the literature, that the hard
spectator contributions significantely reduces the asymmetry arising from the
vertex corrections alone. The value of CP-asymmetry is 10% and is negative like
rho and omega in the Standard Model.Comment: 10 pages, 2 figure
Quintessential Quartic Quasi-topological Quartet
We construct the quartic version of generalized quasi-topological gravity,
which was recently constructed to cubic order in arXiv: 1703.01631. This class
of theories includes Lovelock gravity and a known form of quartic
quasi-topological gravity as special cases and possess a number of remarkable
properties: (i) In vacuum, or in the presence of suitable matter, there is a
single independent field equation which is a total derivative. (ii) At the
linearized level, the equations of motion on a maximally symmetric background
are second order, coinciding with the linearized Einstein equations up to a
redefinition of Newton's constant. Therefore, these theories propagate only the
massless, transverse graviton on a maximally symmetric background. (iii) While
the Lovelock and quasi-topological terms are trivial in four dimensions, there
exist four new generalized quasi-topological terms (the quartet) that are
nontrivial, leading to interesting higher curvature theories in
dimensions that appear well suited for holographic study. We construct four
dimensional black hole solutions to the theory and study their properties. A
study of black brane solutions in arbitrary dimensions reveals that these
solutions are modified from the `universal' properties these solutions have.
This result may lead to interesting consequences for the dual CFTs.Comment: 46 pages, 1 figure. Discussion of black branes added to section
Power Law Entropy Corrected New-Agegraphic Dark Energy in Ho\v{r}ava-Lifshitz Cosmology
We investigate the new agegraphic dark energy (NADE) model with power-law
corrected entropy in the framework of Ho\v{r}ava-Lifshitz cosmology. For a
non-flat universe containing the interacting power-law entropy-corrected NADE
(PLECNADE) with dark matter, we obtain the differential equation of the
evolution of density parameter as well as the deceleration parameter. To study
parametric behavior, we used an interesting form of state parameter as function
of redshift . We found that phantom
crossing occurs for the state parameter for a non-zero coupling parameter, thus
supporting interacting dark energy model.Comment: 13 pages, 2 figures, accepted for publication in 'Canadian J. Phys.
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